Leading by nine runs after the top of the seventh, the Foresters didn't allow St. Joe to score in the bottom of the inning invoking a mercy rule to end the game.
St. Joseph (43-17) will turn around and play Monday at 7:00 p.m. against the Valley Center (Kansas) Diamond Dawgs in an elimination game.
Ryker Fox led the Mustangs throughout the year with a 1.38 ERA, but didn't get much help from his defense Sunday. Fox took the loss giving up nine runs, only one earned, in 5 2/3 innings.
St. Joe finished with only two errors, but both were costly.
With two on and two out in the second, third baseman Evan McDonald fielded a ground ball and fired a high throw to first. It forced Joe Koerper to come off the bag to make the catch. Everyone was safe, including the go-ahead run for the Foresters.
Santa Barbara followed with a two-RBI triple, and a run-scoring single to open a 4-1 lead.
Lucas Powers also committed an error in the sixth, opening the floodgates for another five-run inning.
Trent Hill and Brandon Huske each drove in runs for the Mustangs in the first two innings, but St. Joe only had three hits the rest of the game.